Turbine-bucket.



W. 1 RICE.

TURBINE BUCKET.

APPLICATION FILED MAY27, 1907.

Patented Dec. 1, 1908.

2 SHEETS-SHEET l,

ntor:

l I l l I 1 1 I W. F. RICE.

TURBINE BUCKET.

APPLIOATION FILED MAY27,1907.

Patented Dec. 1, 1908.

UNITED STATES PATENT OFFICE.

WALTER F. RICE, OF QUINCY, MASSACHUSETTS, ASSIGNOR TO GENERAL ELECTRICCOMPANY, A CORPORATION OF NEW YORK.

TURBINE-BUCKET.

Specification of Letters Patent.

Patented Dec. 1, 1908.

Application filed May 27, 1907. Serial No. 375,853.

To all whom it may concern:

Be it known that I, WALTER F. RICE,

aito

In Figs. 6 and 8, supports 3 are attached the web of the wheel 1 and therim thus citizen of the United States, residing at formed is providedwith two rows of buck- Quincy, county of Norfolk, State of Massachusetts, have invented certain new and usei ful Improvements inTurbine-Buckets and Means for Attaching Them, of which the following isa specification.

The invention has reference to elastic fluid turbines and relates moreparticularly to the ets. The number of rows may, however, be varied tosuit operating conditions. The bases of the buckets have thecross-section of a channel bar, namely, two parallel spaced flangesprojecting from a web or central portion connecting them at one end.Ribs i 4 are formed upon the faces of the supports turbine buckets andthe means employed for 3 mounting the bu'ckets upon their supports.

The object of my invention is the provision of an improved constructionwhich attaches the buckets to their supports in a convenient and securemanner, reduces the strain on the j rims of the wheels or supports ofthe movable buckets byreducing the size and weight of the rim, lessensthe cost of manufacture and has other advantages all as set forth in thefollowing specification.

- In the accompanying drawings illustrating embodiments of my invention,Figure 1 is a side view of a group of buckets showing the bucket basebefore it is bent to the curvature i greater width than the flanges,Fig. 5. Fig. 5 the sides of the grooves adjacent the of its support;Fig. 2 is a side view of the buckets shown in Fig. 1 with the base bentto the curvature of a bucket wheel; Fig. 3 is a side view of a group ofbuckets with the base bent to the curvature of an intermediate; Fig. 4is a section through the buckets shown in Figs. 1, 2 and 3; Fig. 5 is asection showing a modification of the means for securing the buckets tothe support; Fi 6 is a section of the rim of a wheel with buc retsattached; Fig. 7 is a perspective view of a modification; and Fig. 8 isa side view of a portion of a wheel having buckets of the type shown inFig. 7 I

For convenience, the turbine buckets are shown mounted on the rim of .awheel 1 carried by and rotating with the main turbine shaft 2, but theinvention is equally well adapted for use on either stationary ormovable intermediates, the buckets projecting radially inward when usedfor the intermediates (Fig. 3) instead of radially outward as whenmounted upon the wheels or rotors 3 by turning parallel grooves thereinand the inner surfaces of the flanges of the channel bar section arefitted to the ribs. The grooves between the ribs and the edges ofthesupport may be of substantially the same width as the anges, Figs. 4 and6, or pf n edge of the rim are undercut. The outer faces of the flangesof the bucket base are also provided with grooves. Suitable stakingpieces 5 securely fasten the base and its attachedbuckets to the rim byengaging the sides of the rim grooves and the outer faces of the flangesand forcing the inner faces into contact with the rib 4. In Figs. 4 andi 6, a similar effect is produced by staking over the edge of the riminto the grooves 12 in the flanges.

The buckets 6 may be made from extruded metal bars and provided with atenon 7 and a shank 8 for uniting them with separate covers 9 and bases10. The tenons are made straight, as in'dicated in dotted lines, F1g.4,and the ends are riveted over in any suitable manner to form thefastening. The hole through the cover may be straight, as in Fig. 6, orits end may be countersunk as in Flg. 4, the angle of the countersinkbeing substantially that of a standard rivet-head. The latterconstruction tends to draw the cover on more tightly when the projectingend of the bucket tenon is riveted over and for. that reason I prefer touse it on large machines.

The bases 10 are made with a suitable channel bar section. The flangesor legal] i of the channel enter the grooves in the supports 3 and aresecured therein byriveting or staking as already described. The stakingoperation subjects the base to a lateral E pressure perpendicular to thegeneral plane of the buckets which force both surfaces of the flangesinto gripping or holding engagement with the support. The hole 13through the ba e 10 has straight parallel sides. Ad- 1' jacent the holethe inner faces of the flanges 11 are beveled or inclined toward eachother,

the angle being substantially that of the standard rivet-head. Thisangle causes the projection or shank 8 of the bucketwhen riveted over todraw the bucket and the basetightly together. Beyond the beveled portionthe flanges are straight and ,parallel.

The channel-shaped bases might be cast or rolled to the curvature of thesupport and suitably finished by machine processes, if necessary, but Ifind it to be more economical to make the basesfrom straight channelbars of steel or some other elastic metal or alloy. The bars ma be castor rolled and then planed or milled to the proper size and shape, orthey may be rolled to exact form and dimensions, if preferred. Thenafter punching the holes 13 for the shanks, the buckets areexpeditiously riveted to the bars by hand or by a suitable machine. Theholes 13 may be punched with their axes at any desired angle to thesurface of the bar to set the buckets at a similar angle. It should alsobe noted that my invention dispenses with the blocks used inman otherturbine constructions to space the individual buckets apart,

. the proper spacing being secured by the 10- cation of the holes 13.The omission of these blocks results in a marked saving in the cost ofmanufacture of all sizes of turbines but particularly so of the smallermachines in which the cost of the spacing blocks often equals or exceedsthe cost of the buckets themselves.

Slits or slots 14 are cut in the straight base or bar by a gang of sawsor milling cutters. These slits extend to within a short distance of theperiphery of the base 10 and are comparatively narrow, but havesuflicient width to permit the bar (Fig. 1) to be easily bent to thecurvature of its support, whether it be the curvature of a bucket-wheel,as in Fig. 2, or the opposite curvature of an intermediate, Fig. 3. Thelength of the base may be equal to the circumference of the support ormay be divided into segments of 7 shorter length, if preferred. Theslotted bars arelaid in the grooves and bent by hand, in all but thelargest sizes, to the necessary curvature, without'deformation while thebuckets of the group are kept together in proper alinement by the metalat the bottom of the slits. After placing the bars in the grooves, theyare staked in as already described. It will not be necessary to stakethem in along the entire circumference, but it can be done, if desired..The fastening will be sufiiciently secure if they are staked atsuitable intervals, while the removal and replacing of the buckets isfacilitated by such a construction. Some of the metal is forced into theslits and acts asa key to hold the bases against longitudinal movement.When the staking is completed, the covers 9 are placed on the tenons 7and secured to the buckets by riveting over the ends of the tenonsbyhand or machine.

In Figs. 7 and 8, I show a modification in which each bucket 6 isprovided with an individual base 15 of channel-shaped crosssection.These bases are assembled in the grooves in the circumference of thesupport and are secured by staking or riveting as before. The innerfaces of the flanges 16 may be beveled as in Figs. 4, 5 and 6, or theymay be provided with rounded corners 17, as in Fig. 7. In the latterform the end of the shank 8 is riveted over to make a rounded headsimilar tothat formed on the tenon 7 in Fig. 6.

In addition to the convenience and reduced cost of the structuredescribed, I am able to use the same channel section for the wheels andintermediates-in all the stages of different turbines varying severalhundred horse-power in their capacity. Thus a few different sizedsections will be suflicient for all sizes of machines. Adequate strengthis obtained and the rim made smaller and lighter than in other forms ofbucket fastenings with which I am familiar.- This reduction of weight atthe rim lessens the centrifugal strain on the rapidly rotating wheels ina very advantageous manner. The gripping or holding surface of the baseis also double that of the buckets having a solid base of substantiallyrectangular cross-section. Buckets of the latter form have but the twoouter faces of the base in engagement with the support, while myimproved base has in addition the inner faces of its flanges in holdingcontact with the support. Hence the structure is doubly safe guardedagainst rupture by bothreducing the centrifugal strains and increasingthe resistance to such strains.

In accordance with the provisions of the patent statutes, I havedescribed the principle of operation of my invention, together w1th theapparatus which I now consider to represent the best embodiment thereof;but I desire to have it understood that the apparatus shown is onlyillustrative, and that the invention can be carried out by other means.

.What I claim as new, and desire to secure by Letters Patent of theUnited States, is,

' 1. In an elastic fluid, turbine, the combination of a grooved support,a bucket, a base mechanically attached to the bucket and provided withparallel flanges or legs which 3. In an elastic fluid turbine, thecombination of a support having a plurality of parallel grooves, abucket base provided with a plurality of flanges each of which entersone of the grooves, and means for securing the base to the support whichsubjects the flanges to lateral pressure in a direction perpendicular tothe plane of the buckets.

4. In an elastic fluid turbine, the combination of a support havinggrooves concentric with the axis of the turbine, a bucket, a base havinga channel-bar cross-section, means for attaching the bucket to the base,and means for securing the flanges or legs of the channel in the groovesby staking or riveting.

5. In an elastic fluid turbine, the combination of a support having arib, a bucket base having two parallel flanges or legs engaging the riband provided with grooves in the flanges, and means engaging the groovesfor securing the base to the support.

6. In an elastic fluid turbine, the combination of a support, a rib onthe support having parallel sides, a bucket, a base rlveted to thebucket and provided with a flange or leg at each side of the rib, andmeans for securing the flanges to the sup ort which engage the outerfaces of the anges and force the inner faces into engagement with therib.

7. In an elastic fluid turbine, the combination of a support having aseries of ribs on its surface, and a bucket base having a flange at eachside, one of the ribs engaging the inner faces of the flanges and theadjacent ribs on either side being staked over to secure the flanges tothe support.

8. In an elastic fluid turbine, the combination of a grooved support,and abucket base having a grooved flange at each side which enters agroove in the support, one edge of the support groove being staked overinto engagement with the groove in the flange to secure the base to thesupport.

9. In an elastic fluid turbine, the combination of a curved support, abucket base of channel-shaped cross-section carrying a group of bucketswhich project outwardly from the portion of the channel joining its legsor flanges, said base being provided with slits to permit it to be madestraight and subsequently bent to the curvature of the support, andmeans for securing the base to the support.

10. In an elastic fluid turbine, the combination of a curved support, abucket base having flanges or legs and provided with slits to permit itto bebent to the curvature of the support, and means for securing theflanges to the support.

11. In an elastic. fluid turbine, the conibination of a curved supporthaving grooves in its surface, a bucket base provided with flanges whichenter the grooves and a series of slits to permit the base to be madestraight and subsequently bent to the curvature of the support, andmeans for securing the flanges in the grooves.

12. In an elastic fluid turbine, the combination of a support havinggrooves concentric with the axis of the turbine, a channel bar forming abucket base and provided with a series of slits to permit the bar to bemade straight and subsequently bent to the curvature of the grooves, andmeans for securing the flanges of the bar in the grooves.

13. In an elastic fluid turbine, the combination of a support havingparallel grooves concentric with the axis of the turbine, a plurality ofbuckets, a channel-bar attached to the buckets to form a base thereforand provided with a plurality of slits extending from the edge of thebar toward the buckets to permit it to be made straight and bent to thecurvature of the grooves after the buckets have been attached toit, andmeans for securing the flanges of the bar in the grooves.

14. In an elastic fluid turbine, the combination of a support havinggrooves concentric with the axis of the turbine, a plural ity of bucketshaving shanks, a bar of channel cross-section to which the shanks areriveted, and means for securing the flanges of the bar in the grooves.

15. In an elastic fluid turbine, the cornbination of a support havinggrooves in its surface concentric with the axis of the turbine, aplurality of buckets having shanks, a channel bar to which the shanksare riveted, the flanges of the bar entering the grooves but projectingbeyond the surface of the support and having their inner surfaces beyondthe support inclined toward each other to receive the upset portion ofthe shank, and means for securing theflanges in the grooves.

16. In an elastic fluid turbine, the combination of a support, aplurality of buckets, a cover attached to one end of the buckets, achannel-bar riveted to the other end of the buckets, and means forsecuring the flanges of the bar to the support.

17. In an elastic fluid turbine, the cornbination of a curved supporthaving grooves, a plurality of buckets, a channel-bar attached to oneend of the buckets, flanges forming part of the bar and entering roovesin the support, grooves in the outer aces of the flanges into which theedges of the grooves in the support are staked over to secure the bar tothe support, and transverse slits in the bar which permit it to bemadestraight and bent to the curvature of the support before securing ittherein.

18. In an elastic fluid turbine, the combination of a support havingparallel grooves concentric with the axis of the turbine, a bucket basehaving a channel-bar cross-section and carrying a group of buckets whichproject outwardly from the portion of the channel joining its flanges orlegs, and means securing the flanges in said grooves.

19. In an elastic fluid turbine, the combination of a support providedwith parallel faces or surfaces, a bucket base having a channel-shapedcross-section, the flanges or legs of the channel engaging said parallelfaces, 'a bucket projectlng outwardly from the portion of the channeljoining its flanges or legs, and means for securing the flanges to thesupport.

20. In an elastic fluid turbine, the combination of a curved support,and a channelshaped bucket base having a group of buckets projectingoutwardly from the portion of the channel joining the two flangesthereof, grooves in the outer face of the flanges, and transverse slitsin said flanges to permit the base to-be made straight and subsequentlybent 'to the curvature of the support, the metal of the support beingforced into said ooves and slits to hold the base against ra ialmovement and also to prevent longitudinal creeping.

21. In an elastic fluid turbine, the combination of a support, a bucketbase of channel-shaped cross section having a hole through the portionof the channel joining the flanges thereof, the inner surface of thechannel adjacent the edge of the'hole being inclined outwardly, a buckethaving a shank which is inserted in and projects through the'hole, theend of the shank being riveted over intoengagement with the inclinedinner surface of the channel to attach the bucket to the base, and meansfor securing the base to the support.

22. In an elastic fluid turbine, the combination of a curved su porthaving grooves formed therein, a plurality of buckets, a basemechanically attached to said buckets and provided with flan es whichenter said grooves, and means or securing the flanges to the support.

23. In an elastic fluid turbine, the combination of a plurality ofbuckets having shanks and shoulders adjacent the shanks, a channel-barforming a base for the buckets and provided with holes in the webportion of the bar joining the flanges thereof to receive the shanks,said shoulders engaging the web portion, a support, and means forsecuring the bar to the support.

In witness-whereof, I have hereunto set my handthis 18 day of May, 1907.

WALTER F. RICE.

Witnesses:

SAMUEL T. MACQUAIM,

LUCY C. Home.

